Electric rock-drill.



Patented Apr. 26; 1910.

IIIUEIVTOR WIT/(8858;

I the rotary motion of the shaft into 1'ecipro-' OLIN' S. PROCTOR, 01 DENVER. COLORADO.

ELECTRIC ROCK-DRILL.

Specification of Letters Patent. Patv nfed A 191() Application filed March 2, 1908. Serial No. 418,779.

To all whom 'it may concern:

Be it known that I, ()mx 9. luocrou, a citizen of the United States of America, residing-in the city and county of l)enve1 and State of Colorado, have invented a new and useful Electric Rock-Drill, of which the following is a specification.

My invention relates to improvements in rock drills.

Theobjects of the invention are: First, to provide a simple. durable and light electric driven rock drill particularly adapted to; sloping but may be used in other worlcl Second, to provide an electric driven rock drill comprising an electric motor which is provided with an extensible shaft which projects into an air pulsating cylinder. Means contained in said cylinder for converting eating motion which causes the air contained in said cylinder to impart an elastic reciprocatillg motion to the hammer piston. Third, to provide an extensible air cylinder between the motor and drill for the purposes of supporting the drill while working and to prevent the vibration of the drillinjuring the motor; and means to supply air to said cylinder. These objects are accomplished by the mechanism illustrated in the accompanying drawings, in which:

Figure 1, is a longitudinal sectional view of the assembled machine. Fig. 2, is a cross section on line M N, Fig. 1. Fig. 3, is an enlarged sectional view of air pump valves. Fig. 4, is a cross section on line 1, Fig. 1. Similar characters of reference refer to similar parts throughout the several views. Referring to the accompanying drawings: The numeral 5 designates an electric motor of which the armature shaft 6 is made hollow to receive the square or hexagonal solid shaft 7 which projects through the end of the cylinder 13 and is provided with'a bevel gear 8 in engagement with the bevel gear 9 on the crank shaft. 10 mounted in bearings 14 and 14 threaded in the walls of the cylinder 13. By means of the crank shaft 10 and the connecting rod 11 the trunk piston .12 is reciprocated in the cylinder 13. The hammer piston 15 is free to move in the cylinder 13 and its operation will be explained,hereafter. The forward end of the cylinder 13 is closed by the striking pm 18 which is surroumled by two metal rings .16 and 16 having a layer of packing 17 interposed between them, then screwing the chuck closes sha nk l9 downon these rings and packing the cylinder air tight. 20 is the drill \\'lllt'll rests looselv in the chuck 12).

i it is a three way valve located in the bypass 3'2 connecting the ends of the cylinder 13 outside of the pistons 12 and 15. The valve 21 is adapted to establish communication be tween the end chambers or either end chamber with the central chamber.

The extensible air cylinder 36 interposed between the motor 5 and the drill cylinder 13 is formed by the cylinder 24 threaded onto the boss 34 formed on the end of the motor 5 and the cylinder 23 which surrounds cylinder if-t with a slidable, air ti ht adaptation. 33 1s a packing ring arounc the armature shaft ('1 to prevent leakage from the cylinder 36.

The air supply in the cylinder 36 is maintained by an air pump comprising the following parts: The eccentric connecting rod 25 operated by the armature shaft (5 reciprocates the piston 26 in the cylinder 27 which is in communication with the inlet check valve 28 and the outlet check valve 29, when the valve 30 is turned to close the passage 31 to the atmosphere, air is forced through the conduit 32 into the cylinder 36. The illustration shows the valve 30 in the position it occupies when the pump is not workiug and the reciprocation of the piston 26 in the cylinder 2? simply causes air to be drawn into and expelled from the cylinder 27 through the passage 31. is a small cock to allow the air to escape from the cylinder 30.

The motor is loosely attached to a board which leans against the wall of the stope or a stall and the end of which rests on the ground, when drilling horizontal holes. When drillin r uppers the board is supported on stulls ant also serves as a platform for the operator to stand on. In most instances, the motor can rest on the ground against the wall or a timber.

The operation of the machine is as follows: The machine bein laced in position, air is forced into the eylm er 36 the drill bit is forced against the rock and the piston 12 is reciprocatcd by the driving mechan ism as above described which causes the air contained in the cylinder 13 to operate the hammer piston in the following manner: As the piston 12 moves forward the air between the pistons 12 and 15 is compressed at the same. time the air behind the piston cation in front of the piston 15 is sufficiently- 1ts backward stroke is taken up bythe elasticity of the air and returned to the forat any desired rate of s eed.

12: is rarefied, so air is drawn through the bypass 22 from in front of the piston 15; when this compression behind and the rarefiwithout departing therefrom. I

I claim: 1. In airo ck drill the combination with a motor, a fluld cylIn der, two pistons in said cylinder, means for reciprocating one of great to overcome its inertia it moves forward to strike the striking pin 18. On the backward stroke the reverse condition obtains and the momentum of the piston 15 in tween said fluid cylinder and said motor.

2. In a rock drill the combination with a ward stroke. It will be observed that the motor and a rock drilling engine, of an ex friction on the rotating shaft 7 can be adjusted byscrewing the gland 37 against the motor and said rockdrilling engine and packing 38 to automatically rotate the drill cylinder. a

3. In a rock drill the combination with a motor of a fluid cylinder, two pistons therein, means for reciprocatin oneof said pistons also contained in sai he operation of feed n the drill against the rock is done by controllin the air pressure in the extensible cylin er 36, which pressure is controlled by the position of the valve 30 as it passes from the position shown tensible air cylinder interposed between said to close the passage 31. When the passage motor and said fluid c linder .and means to 31 is entirely closed the maximum pressure supply air to said flui c linder.

' that the pump will produce will be'obtained. In testimony whereof ailix my signature If the passage 31 is not completely closed in presence of two witnesses. i there will be less pressure in' the cylinder. v OLI'N S. PROCTOR. 36 so the feeding pressure is under the corn \Vitnesses:

trol of the operator. JAMES M. CARIco,

Manifestly the principles of this-invention R. T. N UNN.

may be embodied in a great variety of forms said pistons also containedin said cylinder and an extensible air cylinder interposed be-- tensible 'air cylinder interposed-between said a means to supply air to the" extensible ail cylinder, an ex- 

